include/opencascade/math_FunctionRoots.hxx

0001 // Created on: 1991-05-13
0002 // Created by: Laurent PAINNOT
0003 // Copyright (c) 1991-1999 Matra Datavision
0004 // Copyright (c) 1999-2014 OPEN CASCADE SAS
0005 //
0006 // This file is part of Open CASCADE Technology software library.
0007 //
0008 // This library is free software; you can redistribute it and/or modify it under
0009 // the terms of the GNU Lesser General Public License version 2.1 as published
0010 // by the Free Software Foundation, with special exception defined in the file
0011 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0012 // distribution for complete text of the license and disclaimer of any warranty.
0013 //
0014 // Alternatively, this file may be used under the terms of Open CASCADE
0015 // commercial license or contractual agreement.
0016
0017 #ifndef _math_FunctionRoots_HeaderFile
0018 #define _math_FunctionRoots_HeaderFile
0019
0020 #include <Standard.hxx>
0021 #include <Standard_DefineAlloc.hxx>
0022
0023 #include <NCollection_Sequence.hxx>
0024 #include <Standard_Integer.hxx>
0025 #include <Standard_OStream.hxx>
0026 class math_FunctionWithDerivative;
0027
0028 //! This class implements an algorithm which finds all the real roots of
0029 //! a function with derivative within a given range.
0030 //! Knowledge of the derivative is required.
0031 class math_FunctionRoots
0032 {
0033 public:
0034   DEFINE_STANDARD_ALLOC
0035
0036   //! Calculates all the real roots of a function F-K within the range
0037   //! A..B. without conditions on A and B
0038   //! A solution X is found when
0039   //! abs(Xi - Xi-1) <= Epsx and abs(F(Xi)-K) <= EpsF.
0040   //! The function is considered as null between A and B if
0041   //! abs(F-K) <= EpsNull within this range.
0042   Standard_EXPORT math_FunctionRoots(math_FunctionWithDerivative& F,
0043                                      const double                 A,
0044                                      const double                 B,
0045                                      const int                    NbSample,
0046                                      const double                 EpsX    = 0.0,
0047                                      const double                 EpsF    = 0.0,
0048                                      const double                 EpsNull = 0.0,
0049                                      const double                 K       = 0.0);
0050
0051   //! Returns true if the computations are successful, otherwise returns false.
0052   bool IsDone() const;
0053
0054   //! returns true if the function is considered as null between A and B.
0055   //! Exceptions
0056   //! StdFail_NotDone if the algorithm fails (and IsDone returns false).
0057   bool IsAllNull() const;
0058
0059   //! Returns the number of solutions found.
0060   //! Exceptions
0061   //! StdFail_NotDone if the algorithm fails (and IsDone returns false).
0062   int NbSolutions() const;
0063
0064   //! Returns the Nth value of the root of function F.
0065   //! Exceptions
0066   //! StdFail_NotDone if the algorithm fails (and IsDone returns false).
0067   double Value(const int Nieme) const;
0068
0069   //! returns the StateNumber of the Nieme root.
0070   //! Exception RangeError is raised if Nieme is < 1
0071   //! or Nieme > NbSolutions.
0072   int StateNumber(const int Nieme) const;
0073
0074   //! Prints on the stream o information on the current state
0075   //! of the object.
0076   Standard_EXPORT void Dump(Standard_OStream& o) const;
0077
0078 private:
0079   bool                         Done;
0080   bool                         AllNull;
0081   NCollection_Sequence<double> Sol;
0082   NCollection_Sequence<int>    NbStateSol;
0083 };
0084
0085 #include <math_FunctionRoots.lxx>
0086
0087 #endif // _math_FunctionRoots_HeaderFile